1. Field of the Invention
The present invention relates to a substrate processing method and substrate processing apparatus for polishing the notched portion or the like of a semiconductor substrate with a polishing tape.
2. Description of the Related Art
Conventionally, to polish the notched portion of a semiconductor wafer, a polishing tape with abrasive grains is brought into contact with the notched portion, and is slid in a direction perpendicular to the wafer surface (Jpn. Pat. Applin. KOKAI Publication No. 9-76148).
With this method, depending on the polishing conditions, the wafer may be damaged or the notched portion may be ground nonuniformly. This is due to the following reason. Although the polishing tape is curved along the notched portion by the polishing load, depending on the polishing conditions, the edge of the polishing tape catches on the notched portion. If the polishing tape deforms insufficiently, the area of that portion of the polishing tape which is in contact with the polishing surface becomes narrow. Then, stable polishing cannot be performed easily. In this case, it is difficult to perform uniform polishing, and the entire surface of the polishing tape is not used, which is uneconomical.
If the polishing conditions are not inappropriate in this manner when polishing the notched portion, the edge of the polishing tape may damage the wafer, or uniform polishing cannot be performed. To conform the polishing tape to the shape of the notched portion, the polishing tape may be made thin. When the polishing tape is made thin, however, durability against pulling suffers. Therefore, to thin the polishing tape is limited.